迭代器模式 c#

　　抽离集合对象的遍历职责。

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

namespace ConsoleApplication1
{
    class Program
    {
        public interface IListCollection
        {
            Iterator GetIterator();
        }


        public interface Iterator
        {
            bool MoveNext();
            object GetCurrent();
            void Next();
            void Reset();
        }


        public class ConcreteList:IListCollection
        {
            private int[] collection;

            public ConcreteList()
            {
                collection = new int[] {2, 4, 6, 8};
            }

            public Iterator GetIterator()
            {
                return new ConcreteIterator(this);
            }

            public int Length
            {
                get { return collection.Length; }
            }

            public int GetElement(int index)
            {
                return collection[index];
            }

        }

        public class ConcreteIterator:Iterator
        {
            private ConcreteList cList;
            private int index;

            public ConcreteIterator(ConcreteList clist)
            {
                this.cList = clist;
                index = 0;
            }

            public bool MoveNext()
            {
                if (index < cList.Length)
                {
                    return true;
                }

                return false;
            }

            public object GetCurrent()
            {
                return cList.GetElement(index);
            }

            public void Next()
            {
                if (index < cList.Length)
                {
                    index++;
                }
            }

            public void Reset()
            {
                index = 0;
            }
        }

        static void Main(string[] args)
        {
            Iterator iterator;
            IListCollection cList = new ConcreteList();
            iterator = cList.GetIterator();

            while (iterator.MoveNext())
            {
                Console.WriteLine(iterator.GetCurrent().ToString());
                iterator.Next();
            }
        }
    }
}